package com.example.forum.interceptor;


import com.example.forum.config.AppConfig;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;


/**
 * 自定义拦截器
 */
@Component
public class LoginInterceptor implements HandlerInterceptor {

    @Value("${forum.login.url}")
     private String defaultUrl;
    /**
     * 前置处理（对请求的前置处理）
     * @return true 继续流程  false 中断流程
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        HttpSession session = request.getSession(false);
        if (session != null && session.getAttribute(AppConfig.USER_SESSION) != null) {
            //校验通过，登录成功
            return true;
        }

        if (!defaultUrl.startsWith("/")) {
            defaultUrl = "/" + defaultUrl;
        }
        //检验不通过，跳转到登录页面
       response.sendRedirect(defaultUrl);
        return false;
    }
}
